Emboss pattern processing apparatus and embossed sheet

ABSTRACT

A method of an emboss pattern process has steps of transferring an emboss pattern onto a thermoplastic resin sheet by using an emboss patterning roller; lustering the opposite face of the embossed face of the thermoplastic resin sheet by using a lustering means having a mirror face member; and peeling the thermoplastic resin sheet from the emboss patterning roller at a lower temperature than a temperature for transferring the emboss pattern. The emboss patterning roller has a roller body, having a face embossed with the pattern, and sealing rings attached on each side face of the roller body, in which the roller body and the sealing ring has a passage for flowing a cooling medium from one sealing ring through the roller body to the other sealing ring.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a divisional of application Ser. No. 08/882192, filed Jun. 25, 1997.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to a method of an emboss pattern process,emboss pattern processing apparatus, and an embossed sheet, which isused for the production of an optical precision embossed sheet, such asa reflector, a prism sheet, a fresnel lens and so on.

[0004] 2. Description of the Related Art

[0005] In recent years, a reflective ability sheet (a plastic reflectionsheet), undergoing a micro-prism process on the surface of athermoplastic resin sheet, has been employed in the reflection panelfield, the fashion field, an architecture field and so on.

[0006] In the United States, the use of a glass bead type and a cubecorner type are approved as the aforementioned reflective ability sheet.Commonly, the reflective ability sheet of the glass bead type issuperior in short-distance visibility, and the reflective ability sheetof the cube corner type is superior for long-distance visibility andluminance created by optical reflection.

[0007] In the production of the reflective ability sheet of the cubecorner type, an emboss pattern on an emboss pattern forming die (or apattern embossing die) should be precisely transferred onto thethermoplastic resin sheet.

[0008] Therefore, it is especially important that the thermoplasticresin sheet is pressed onto the emboss pattern forming die (or thepattern embossing die) with appropriate pressure, and further, thepressure is continuously added for a predetermined period of time.

[0009] As conventional methods for producing the reflective abilitysheet serving the above requirement, for example, a continuouslypressing method (Japanese Patent Application Publication No.Sho60-56103), a belt method (Japanese Patent Application Publication No.Hei5-17023), and a roller method (an example relating to FIG. 9 inJapanese Patent Application Publication No. Hei3-43051) are proposed.

[0010] With the continuously pressing method, emboss pattern formingdies (or pattern embossing dies) are sequentially pressed onto a sheetmaterial of solid phase, laid on a belt and continuously supplied withplural pressing means having a heating or cooling function to transferpatterns onto the sheet material.

[0011] With the belt method, a belt having an emboss pattern and athermoplastic resin sheet are pressed between a pair of rollers totransfer patterns onto the sheet.

[0012] With the roller method, an emboss pattern is transferred onto asheet by using a roller forming the emboss pattern on its outercircumferential face.

[0013] According to the aforementioned continuously pressing method, theproduction speed is slow and apparatus is complicated and large in size.

[0014] According to the belt method, the belt itself carries the embosspattern, so that apparatus is large in size, and a disadvantage arisesconcerning the endurance of the belt as a pattern embossing die.

[0015] And, according to the roller method, the production speed isfaster and the endurance is better. But, the temperature of the sheet isnot effectively controlled to increase when the emboss pattern istransferred onto the sheet and decreased when the sheet after beingembossed is peeled from the roller, resulting in disadvantagesconcerning the pattern reproducibility and the peeling properties. Inother words, the apparatus is not structured to have a large differencein temperature between an area of the roller where the pattern istransferred, and an area of the roller where the sheet is peeled, thusnot allowing the precise pattern reproducibility and the smoothlypeeling properties to be obtained.

[0016] And further, the reflective ability sheets obtained by theconventional producing methods are not satisfied in regard to thereflecting properties.

SUMMARY OF THE INVENTION

[0017] A method of an emboss pattern process according to the presentinvention is characterized by including the following steps of:transferring an emboss pattern onto a thermoplastic resin sheet by usingan emboss patterning roller; lustering (setting a gloss on) the oppositeface of the embossed face of the thermoplastic resin sheet by using alustering means having a mirror face member; and peeling thethermoplastic resin sheet from the emboss patterning roller at a lowertemperature than a temperature for transferring the emboss pattern.

[0018] It is advisable that the temperature for transferring the embosspattern is defined to be more than the Vicat softening point of thethermoplastic resin sheet, though also depending upon the type of resinused, the temperature of the thermoplastic resin sheet before beingembossed, and so on. The Vicat softening point is a softeningtemperature of the thermoplastic resin sheet, in which the measuringmethod of the above temperature is based on JIS K7206.

[0019] A difference in the temperature in the pattern transfer step andthe lower temperature than that in the pattern transfer step can beproperly defined, for example, more than 10° C., preferably more than20° C., also depending on the pressure or the type of resin. Thedifference in temperature of less than 10° C. causes the lack of coolingability in the peeling step, so that the precise embossed pattern cannotbe obtained. The upper limit of the difference in temperature is notespecially defined, but it is preferable to be less than 150° C. In thedifference in temperature of more than 150° C., the endurance of theroller becomes inferior or the production speed becomes slower,resulting in higher cost.

[0020] When the thermoplastic resin sheet is lustered by the lusteringmeans, the face-pressure is more than 0.01 MPa. If the face-pressuredecreases less than 0.01 MPa, the uniformity of gloss is likely todeteriorate.

[0021] Incidentally, a thermoplastic resin film having a relativelydifferent thickness from the then no plastic resin sheet can be used.

[0022] Emboss pattern processing apparatus according to this presentinvention is characterized by including: an emboss patterning roller fortransferring the emboss pattern onto a thermoplastic resin sheet; alustering means, having a mirror face member, for lustering the oppositeface of the embossed face of the thermoplastic resin sheet; and acooling means for cooling the thermoplastic resin sheet peeled from theemboss patterning roller, to a lower temperature than a temperature fortransferring the emboss pattern.

[0023] In the emboss pattern processing apparatus according to thepresent invention, it is advisable that the emboss patterning roller hasa roller body having a face for embossing a pattern; and a sealing ringattached on each side face of the roller body, in which the roller bodyand the sealing ring are formed with a passage for flowing a temperaturecontrolling medium for cooling from the one sealing ring through theroller body to the other sealing ring.

[0024] As the temperature controlling medium, water, silicone oil, oilfor controlling temperature, or the like can be selectively used.

[0025] According to the present invention, the passage is formed alongan area of the roller body which is required to be cooled, and thetemperature controlling medium with the suitable temperature is flowninto the passage, thereby the temperature when the thermoplastic resinsheet is peeled off the emboss patterning roller is decreased to belower than the temperature when the pattern is embossed. In other words,the aforementioned passage for flowing the temperature controllingmedium comprises a cooling means.

[0026] The temperature controlling medium with the fixed temperature iscontinuously flowed from one sealing ring through the roller body to theother sealing ring, thereby allowing the temperature of the area of theroller body which is required to be cooled to be accurately controlled.

[0027] The passage in the roller body can be plural passage-tubes formedalong and in the vicinity of the outer circumferential face of theroller body.

[0028] The diameter of the passage-tube and the number of passage-tubesare selectively decided so that the temperature of the area of theroller body which is required to be cooled is effectively controlled bythe temperature controlling medium flown through the aforementionedpassage-tubes. And, the suitable diameter of the passage-tube and thesuitable number of passage-tubes may be determined according to the sizeof the roller used.

[0029] Where the passage-tube is a sectional circle, the inner diameteris selectively decided, preferably, for example, approximately 1 mm to100 mm. Depending upon the temperature of the temperature controllingmedium, but if the inner diameter is less than 1 mm, the sufficient flowrate cannot be obtained. But, if the inner diameter is more than 100 mm,the amount of temperature controlling medium for cooling remaining inthe passage-tube increases, so that the heating efficiency in rotatingthe roller from the area for peeling the sheet toward the area fortransferring pattern decreases. It is advisable that the sealing ring isformed therein with a groove linking to the plural passage-tubes of theall passage-tubes in the roller body.

[0030] For example, when the area of the roller body where thetemperature is needed to be controlled is defined at a θ degree angleoriginating from the axis of the roller body, the groove can be formedto flow the temperature controlling medium into the passage-tubes in thearea created by the θ degree angle. The θ degree angle is decidedaccording to the pattern transfer speed, and is not especially limited.But where the θ degree angle is defined at an extremely small value, itis impossible to effectively control the temperature. Where the θ degreeangle is defined at an extremely large value, it is difficult to controlthe temperature in the cooling step or the heating step when the passagefor flowing the temperature controlling medium for heating is furtherformed in order to simultaneously carry out the cooling step and theheating step.

[0031] It is desirable that the sealing ring is formed therein with apassage for flowing a temperature controlling medium for heating inaddition to the passage for flowing the temperature controlling mediumfor cooling; and the sealing ring is formed therein with grooves linkingto the passages.

[0032] The cooling medium and the heating medium flow into the twopassages, so that the heating medium flows through the area of theroller where the pattern is transferred, and the cooling medium flowsthrough the area of the roller where the sheet is peeled, thus creatingthe large difference in the temperature for improving the patternreproducibility and the peeling properties

[0033] It is desirable that the degree of surface roughness of themirror face member of the lustering means is less than 3S.

[0034] If the degree of surface roughness if more than 3S, the luminancedecreases because light irregularly reflects on a non-embossed face ofthe thermoplastic resin sheet. Preferably, it is less than 1S.

[0035] The mirror face member can be a metal belt having the mirrorface, a metal-faced elastic roller having the mirror face, or the like.

[0036] The belt is preferably made of stainless. The thickness of thebelt is defined selectively, for example, 0.3 mm to 1.5 mm, preferably,0.5 mm to 0.8 mm.

[0037] The metal-faced elastic roller has a tubular metal member locatedon the outer surface of the metal-faced elastic roller and a tubularelastic member located inside of the tubular metal member.

[0038] The roller body has an outer cylinder section having the face forembossing the pattern; a middle cylinder section inserted into theinside of the outer cylinder section and having the passage; and aninner cylinder section inserted into the inside of the middle cylindersection, in which the middle cylinder section has a greater linearexpansion coefficient than that of the outer cylinder section, and theinner circumferential face of the middle cylinder section is formed tobe a tapered shape having the same degree angle as a tapered shape ofthe outer circumferential face of the inner cylinder section.

[0039] The middle cylinder section is heated while being inserted intothe outer cylinder section, thereby the middle and outer cylindersections are coupled to each other because of the difference of thethermal expansion coefficients of both sections.

[0040] Further, the inner cylinder section is inserted into the middlecylinder section during the aforementioned heated expansion after themiddle cylinder section is inserted into the outer cylinder section, andthen the inner and middle cylinder sections are united by a shrinkageforce created when the temperature of the sections returns from the hightemperature to a room temperature.

[0041] In the emboss pattern processing apparatus according to thepresent invention, it is advisable that the roller body of the embosspatterning roller is coupled with a rotation shaft for rotating theroller body, rotation shaft to pass through the sealing rings.

[0042] More specifically, in the emboss pattern process, only the rollerbody is rotated and the aforementioned sealing ring is in a stationaryposition. Therefore, the temperature controlling medium flows into onlythe passage-tubes in the roller body which are linked to the groove inthe stationary sealing ring by rotating the roller body.

[0043] Preferably, a heating means for heating an area of the rollerbefore the emboss pattern is transferred is provided in the vicinity ofthe emboss patterning roller.

[0044] The specific example of the heating means is selectively decided,for example, an infrared heater and so on. The area of the roller wherethe pattern is transferred is effectively heated by the outside heatingmeans.

[0045] The emboss pattern can be a cube corner type.

[0046] The embossed sheet according to the present invention is producedby the following method: transferring an emboss pattern onto athermoplastic resin sheet by using an emboss patterning roller;lustering the opposite face of the embossed face of the thermoplasticresin sheet by using a lustering means having a mirror face member; andpeeling the thermoplastic resin sheet from the emboss patterning rollerat a lower temperature than a temperature for transferring the embosspattern.

[0047] The conditions, as to the temperature when the emboss pattern istransferred, the temperature when the thermoplastic resin sheet ispeeled from the emboss pattern roller, and so on, are the same as theconditions explained in the method for the emboss pattern processaccording to the present invention.

[0048] The specific type of the used thermoplastic resin is selectivelydecided. But where the embossed sheet is used as a plastic reflectingplate, the ideal material is an amorphous resin, such as polyvinylchloride, polycarbonate, acryl resin (PMMA or the like), and so on,because of the high transparency and that the pattern embossed on thesheet is not easily transfigured even in the shrinkage.

[0049] And further, the thickness of the thermoplastic resin sheet isnot particularly defined, but, preferably it is, for example,approximately 0.07 mm to 30 mm. If it is thinner than 0.07 mm, thepattern-transferring properties can deteriorate, and if it is thickerthan 30 mm, the heating and cooling efficiency or the efficiency ofproduction can deteriorate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0050]FIG. 1 is a front view of emboss pattern process apparatusrelating to the preferred embodiment of the present invention;

[0051]FIG. 2 is a front view of an emboss patterning roller relating tofirst embodiment;

[0052]FIG. 3 is a perspective view of a roller body of the embosspatterning roller relating to the first embodiment;

[0053]FIG. 4 is a disassemble sectional view of the emboss patterningroller relating to the first embodiment;

[0054]FIG. 5 is a perspective view of a sealing ring relating to thefirst embodiment;

[0055]FIG. 6 is a front view of a pattern formed on the surface of anouter cylinder section;

[0056]FIG. 7 is a sectional view taken along the A-A line in FIG. 6;

[0057]FIG. 8 is a plane view of an embossed sheet;

[0058]FIG. 9 is a sectional view taken along the B-B line in FIG. 8;

[0059]FIG. 10 is a perspective view of another structure of the sealingring;

[0060]FIG. 11 is a front view of emboss pattern process apparatusrelating to the second embodiment of the present invention;

[0061]FIG. 12 is a front view of emboss pattern process apparatusrelating to the third embodiment of the present invention;

[0062]FIG. 13 is a front view of emboss pattern process apparatusrelating to the fourth embodiment of the present invention; and

[0063]FIG. 14 is a front view of emboss pattern process apparatusrelating to the fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) First Embodiment

[0064] An emboss pattern processing apparatus 10 according to the firstembodiment will be explained below with reference to FIG. 1 through FIG.9.

[0065] As shown in FIG. 1, the emboss pattern processing apparatus 10 iscomposed of a heating means 12 for heating a thermoplastic resin sheet11 before an emboss pattern being transferred; an emboss patterningroller 13; an elastic roller 14 promoting to transfer the emboss patternonto the thermoplastic resin sheet 11; a lustering means 15 forlustering the opposite face of the embossed face of the thermoplasticresin sheet 11; and a peeling roller 16 peeling the thermoplastic resinsheet 11 after being embossed with the pattern.

[0066] As shown in FIG. 2 through FIG. 5, the emboss patterning roller13 has a roller body 17 and sealing rings 18A and 18B each attached ontoa side face of the roller body 17.

[0067] The roller body 17 is, in turn, composed of an outer cylindersection 19; a middle cylinder section 21 inserted into the inside of theouter cylinder section 19; and an inner cylinder section 22 insertedinto the inside of the middle cylinder section 21.

[0068] As shown in FIG. 6 and FIG. 7, the outer cylinder section 19 isformed on its outer surface with a pattern 23 in order to emboss theemboss pattern on the thermoplastic resin sheet 11. The pattern 23 is atriangular pyramidal diamond cut pattern of a cube corner type.

[0069] As to the middle cylinder section 21, a cutout portion 25 isformed on each outer circumferential face of opening end portions 24Aand 24B, formed at both ends of the roller body 17, to engage with thesealing rings 18A and 18B, in which a female screw 26 is formed on theinner circumferential face of the opening end portion 24A. The innercircumferential face of the middle cylinder section 21 is formed to makea taper shape which the diameter of the middle cylinder section 21 isincreased from the opening end portion 24A toward the opening endportion 24B. In the middle cylinder section 21, plural sectionalcircular passage-tubes 27 as a passage for flowing a temperaturecontrolling medium are formed along and in the vicinity of the outercircumferential face of the middle cylinder section 21 with equidistancefrom one another. A linear expansion coefficient of the material usedfor the middle cylinder section 21 is larger than that of the outercylinder section 19.

[0070] As to the inner cylinder section 22, it has also the outercircumeferential face formed to make a tapered-shape which the diameterof the inner cylinder section 22 increases from the opening end portion24A toward the opening end portion 24B. The taper angle in the innercylinder section 22 agrees with the taper angle created by the innercircumferential face of the middle cylinder section 21. A male screw 28is formed on the outer circumferential face of the opening end portion24B. And, the inside of the inner cylinder section 22 is hollow.

[0071] Concerning a structure of the roller body 17, the middle cylindersection 21 is heated after being inserted into the outer cylindersection 19. During the above heated expansion, the inner cylindersection 22 is screwed into the middle cylinder 21. The middle and innercylinder sections 21 and 22 are coupled because of the difference in thethermal expansion coefficients of the sections 21 and 22, and further,are unitedly assembled by a shrinkage force created when the temperatureof the sections returns from the heated temperature to a roomtemperature.

[0072] The inner cylinder section 22 is coupled with a hollow rotationshaft 29 to keep the section 22 and shaft 29 being linked. In the embosspattern process, a temperature controlling medium is flown in thehollows.

[0073] As shown in FIG. 5, each of the sealing rings 18A and 18B has ahole 31 at the center to pass the rotation shaft 29. On the face of thesealing ring mounted onto each side face of the roller body 17, acircular cavity 32 is formed to engage with the cutout portion 25 of themiddle cylinder section 21, in which a port 33 as the passage forflowing the temperature controlling medium is formed between the cavity32 and the outer side face of the sealing ring. A groove 34 linking tothe port 33 is formed in a circular shape in the cavity 32.

[0074] The groove 34 is formed in a size allowing the groove 34 to linkto some of the passage-tubes 27 of all plural passage-tubes 27 formed inthe roller body 17, when the sealing rings 18A and 18B are fitted withthe roller body 17. More specifically, in controlling the temperature ofthe roller body 17, for example, where an area of the roller body 17required to be cooled, is defined at a θ degree angle originating fromthe axis of the roller body 17, the size of the groove 34 allows thetemperature controlling medium to flow into the aforementioned pluralpassage-tubes 27 entering the θ degree angle. The temperaturecontrolling medium for cooling 35 flows into the above pluralpassage-tubes 27 linking to the groove 34, so that the area where thecooling medium 35 flows through the passage-tubes 27 is for an areawhere the sheet 11 is peeled from the roller body 17.

[0075] An elastic body 36, such as silicone rubber or the like, coversthe surface of the elastic roller 14. The elastic body 36 is 1 mm to 50mm thick. The elastic roller 14 is abutted on the emboss patterningroller 13 via the sheet 11 at a position where the thermoplastic resinsheet 11 is led onto the roller 13.

[0076] The lustering means 15 is composed of a first roller 41 and asecond roller 42, which are provided in the vicinity of the embosspatterning roller 13, and further a metal endless belt 43 mounted ontothe rollers 41 and 42. The rollers 41 and 42 are provided therein with atemperature control means and linked to a rotation driving means. Theendless belt 43 is placed to press onto the opposite face of theembossed face of the sheet 11, touched onto the emboss patterning roller13, between the rollers 41 and 42. The endless belt 43 is a mirror facehaving the degree of surface roughness of less than 3S.

[0077] The peeling roller 16 abuts onto the emboss patterning roller 13via the sheet 11 at a position where the sheet 11 is peeled from theroller 13. The peeling roller 16 is located across from the elasticroller 14 on the almost opposite side of the emboss patterning roller13.

[0078] The heating means 12 has an infrared heater and is provided toheat on both faces of the sheet 11.

[0079] Incidentally, in the processing apparatus 10, from the embosspatterning roller 13 on the opposite side of the roller 14, a coolingroller 44 can be placed to abut onto the outer circumferential face ofthe elastic roller 14. The surface temperature of the elastic roller 14can be controlled by the cooling roller 44.

[0080] An air blowing device 45 can be placed in the vicinity of thepeeling roller 16 to cool the sheet 11 peeled from the emboss patterningroller 13.

[0081] And further, a third roller 46 can be provided in a circle of theendless belt 43 to adjust the tension of the endless belt 43.

[0082] The emboss pattern process for the thermoplastic resin sheet 11is carried out as the following with the use of the emboss patternprocessing apparatus 10.

[0083] As shown in FIG. 1 through FIG. 3, while the roller body 17 isrotated and the endless belt 43 is run on the rollers, the thermoplasticresin sheet 11 heated by the heating means 12 is continuously suppliedonto the emboss patterning roller 13. The cooling medium 35 iscontinuously flown from the sealing ring 18A through the passage-tubes27 in the roller body 17 toward the sealing ring 18B.

[0084] The heatedly softened thermoplastic resin sheet 11 isface-pressed onto the roller 13 by the elastic roller 14 having theelastic body 36 to be embossed with the pattern formed on the outercylinder section 19.

[0085] The sheet 11 after being embossed is moved with the rotation ofthe roller body 17, and the opposite face of the embossed face of thesheet 11 is pressed onto the mirror face of the endless belt 43 by theendless belt 43 to be transferred for the luster. The sheet 11 afterbeing lustered is delivered to the opposite side of the roller body 17from the elastic roller 14.

[0086] In the roller body 17, the cooling medium 35 flown into thegroove 34 of the sealing ring 18A is continuously flown into the pluralpassage tubes 27 in the roller body 17, which are linked to the groove34, and sequentially, discharged through the groove 34 of the sealingring 18B. Since the cooling medium 35 with the specified temperature iscontinuously flown through the plural passage-tubes 27 which is locatedon the area where the sheet 11 is peeled from the roller body 17, thepeeled area of the sheet 11 is effectively cooled. And then, the sheet11 cooled by the cooling medium 35 is peeled from the roller body 17 bythe peeling roller 15, thus obtaining an embossed sheet 11 A with anemboss pattern 47 (see FIG. 8 and FIG. 9).

[0087] The sealing rings 18A and 18B according to the embodiment areeach formed with the groove 34 in the cavity 32. But, as shown in FIG.10, a sealing ring 38 can be formed to have, in addition to the groove34, another groove 37 formed along the area where the emboss pattern onthe roller body 17 is transferred onto the sheet 11. A port 39 is formedas the passage for the temperature controlling medium 35 to link to thegroove 37.

[0088] In the emboss pattern processing apparatus 10 with the sealingring 38, the temperature controlling medium for heating represented byarrow 65, flows into the plural passage-tubes 27 assigned along the areawhere the pattern is transferred, in order to heat the area of theroller body 17, where the pattern on the roller 17 is transferred. Andfurther, the cooling medium represented by arrow 35, flows into theplural passage-tubes 27 at the area for peeling the sheet 11 in order tocool the area of the roller body 17 from which the sheet 11 is peeled.

Second Embodiment

[0089] An emboss pattern processing apparatus 10 according to theembodiment will be explained below with reference to FIG. 11.

[0090] A characteristic point of the emboss pattern processing apparatus10 as compared with the processing apparatus 10 of the first embodimentis that the pattern transfer and the luster are simultaneously carriedout by the endless belt 43.

[0091] More specifically, a pressing roller 48 is provided in the circleof the endless belt 43 to abut onto the emboss patterning roller 13 viathe endless belt 43 and the sheet 11. The pressing roller 48 has atubular elastic body 36 on its outer circumferential face.

[0092] The third roller 46 for adjusting the tension is provided in thecircle of the endless belt 43.

[0093] The other structures of the emboss patterning roller 13, the belt43 and so on are the same as that of the first embodiment.

[0094] In the method of the emboss pattern process with the use of theaforementioned processing apparatus 10, the sheet 11 embossed with thepattern between the emboss patterning roller 13 and the pressing roller48 is lustered by the belt 43 while running on the outer circumferentialface of the roller 13. And then, in the same way as the firstembodiment, the sheet 11 is cooled at the area for peeling the sheet andpeeled from the roller 13.

Third Embodiment

[0095] An emboss pattern processing apparatus 10 relating to the thirdembodiment will be described below with reference to FIG. 12.

[0096] As compared with the processing apparatus 10 of the firstembodiment, the characteristic points of the processing apparatus 10 inthis embodiment are that a heating means 20 is provided along and in thevicinity of the outer circumferential face of the emboss patterningroller 13, and that a metal-faced elastic roller 49 replacing theendless belt 43 also serves as a peeling roller.

[0097] More specifically, the heating means 20 is provided in thevicinity of the outer circumferential face of the emboss patterningroller 13 to heat an area of the roller 13 up to the start of thepattern transfer during rotation.

[0098] The metal-faced elastic roller 49 is composed of a tubular metalmember 51 on the outside and a tubular elastic member 52 located on theinside of the tubular metal member 51. The tubular metal member 51 ismade of stainless and has a mirror face having the degree of surfaceroughness of less than 3S. The metal-faced elastic roller 49 is providedat the area for peeling the sheet 11 to be pressed onto the roller 13through the sheet 11.

[0099] In the method of the emboss pattern process with theaforementioned processing apparatus 10, the tubular elastic member 52 ofthe metal-faced elastic roller 49 is elastically deformed and touched toface-pressure onto the pattern-transferred sheet 11, thereby the mirrorface of the metal section 51 is transferred onto the opposite face ofthe embossed face of the sheet 11 and the sheet 11 is simultaneouslycooled. Just after that, the sheet 11 is peeled from the roller 13.

[0100] According to the aforementioned processing apparatus 10, the areaof the roller body 17, where the pattern is transferred onto the sheet,is heated by the heating means 20, and moreover, the area of the rollerbody 17, where the pattern is transferred, is further heated by theheating medium 35, whereby the sheet 11 is effectively heated asrequired for transferring the pattern.

Fourth Embodiment

[0101] An emboss pattern processing apparatus 10 according to the fourthembodiment will be explained with reference to FIG. 13.

[0102] As compared with the processing apparatus 10 of the firstembodiment, points characterizing the processing apparatus 10 of thisembodiment are that an endless belt 53 for cooling is provided and thatthe air blowing device 45 for cooling the sheet 11 is provided.

[0103] More specifically, the cooling endless belt 53 is mounted onfourth and fifth rollers 54 and 55 which are located in the vicinity ofthe emboss patterning roller 13. A part of the outer circumferentialface of the endless belt 53 between the rollers 54 and 55 presses theopposite face of the embossed face of the sheet 11 touched onto theemboss patterning roller 13.

[0104] The air blowing device 45 is provided to blow air into a spacebetween the emboss patterning roller 13 and the fifth roller 55.

[0105] In the method of the emboss pattern process with the use of theaforementioned processing apparatus 10, after the lustered sheet 11 iscooled by the cooling endless belt 53, the sheet 11 is further cooled bythe air blowing device 45 and peeled from the emboss patterning roller13.

Fifth Embodiment

[0106] An emboss pattern processing apparatus relating to the fifthembodiment will be explained below with reference to FIG. 14.

[0107] Different points of the processing apparatus of this embodimentfrom that of the fourth embodiment are the formation of the endless belt53 for cooling and the air blowing device 45 for cooling the sheet 11.

[0108] More specifically, concerning the endless belt 53, only thefourth roller 54 is abutted on the emboss patterning roller 13 via thesheet 11, and the fifth roller 55 is located at a distance from theroller 13. The fourth roller 54 has the elastic body 36 on its outercircumferential face.

[0109] The two air blowing devices 45 are provided to blow air into aspace between the emboss patterning roller 13 and the fourth roller 54from both sides.

[0110] In the method of the emboss pattern process with the use of theaforementioned emboss pattern processing apparatus 10, the lusteredsheet 11 is cooled by an area of the endless belt 53, touched onto thefourth roller 54, and the two air blowing devices 45, and peeled fromthe emboss patterning roller 13.

Experiment 1

[0111] As to the first embodiment, the cube comer type emboss pattern isprocessed onto the thermoplastic resin sheet 11 by using the followingapparatus and under the following conditions.

[0112] The outer cylinder section 19 is formed by welding the mutuallyfaced short-sides of a rectangular nickel-made plate (0.6 mm thick) byargon welding. The inner diameter in a room temperature is 143.1 mm, theface length (the length along the axis of the roller) is 220 mm.

[0113] The middle cylinder section 21 is made of aluminium (5052), andthe outer diameter in a room temperature is 142.8 mm; the face length is250 mm; the inner diameter of one opening end portion is 110.25 mm; theinner diameter of the other opening end portion is 119 mm; and the taperis one degrees.

[0114] The inner cylinder section 22 is made of stainless (SS41), andthe outer diameter of one opening end portion in a room temperature is110.55 mm; the outer diameter of the other opening end portion is 119.3mm; the inner diameter is 50 mm; the face length is 250 mm; and thetaper is one degrees.

[0115] The passage-tubes 27 are the inner diameter of 8 mm each, whichare formed along and in the vicinity of the outer circumferential faceof the middle cylinder section 21 with equidistance of 1 mm from oneanother.

[0116] The cooling medium 35 is silicone oil.

[0117] Each of the sealing rings 18A and 18B is 150 mm in diameter and15 mm thick.

[0118] The emboss patterning roller 13 is 150 mm in diameter and 300 mmwide.

[0119] The peeling roller 15 is 50 mm in diameter.

[0120] The elastic roller 14 is 100 mm in diameter and 340 mm wide. Theelastic body 36 is made of silicone resin, in which its hardness(conforming to JIS K6301 A) is 60 degrees.

[0121] The endless belt 43 is 15 mm thick and 1S of the degree ofsurface roughness.

[0122] The temperature in the pattern transfer step is 130° C., and thepressure (a linear pressure) is 200 N/cm.

[0123] The surface temperature of the belt in the luster step is 120° C.

[0124] The temperature of the peeling roller 15 is 15° C.

[0125] The processing speed is 1 m/min.

[0126] The thermoplastic resin sheet 11 is 0.3 mm thick, and made ofpolyvinyl chloride of 1,300 polymerization degrees, consisting of 50 wt% of plasticizer (DOP: di-2-ethyl hexyl phthalate).

[0127] The first roller 41 is 200 mm in diameter; 300 mm wide; and thetemperature 100° C.

[0128] The second roller 42 is 200 mm in diameter; 300 mm wide; and thetemperaure 30° C.

Experiment 2

[0129] As to the second embodiment, the cube comer type emboss patternis processed onto the thermoplastic resin sheet 11 by using the sameapparatus and under the same conditions as Experiment 1. As to theemboss patterning roller 13 of Experiment 2 in the same way asExperiment 1, the difference in the temperature is created between thearea for transferring the pattern and the area for peeling the sheet 11by flowing the cooling medium through the area for peeling the sheet 11.

Comparison 1

[0130] Concerning Experiment 1, the emboss pattern is processed onto theresin sheet 11 without the cooling medium 35 is flown into the rollerbody 17. Both of the temperatures in the pattern transfer step and thepeeling step are 120° C. The other conditions are the same as Experiment1.

Comparison 2

[0131] Concerning Experiment 1, the emboss pattern is processed onto theresin sheet 11 without the cooling medium 35 being flown into the rollerbody 17. Both of the temperatures for the pattern transfer step and thepeeling step are 100° C. The other conditions are the same as Experiment1.

Comparison 3

[0132] Concerning Experiment 1, the emboss pattern is processed onto theresin sheet 11 without the luster step.

[0133] As to the embossed sheets 11A obtained in Experiments 1 and 2 andComparisons 1, 2 and 3, the reflecting properties are evaluated. Theevaluation of the reflecting properties is carried out as to luminance.

[0134] The evaluated results is shown in Table 1. The evaluationrelating to the reflecting properties in Table 1 is as follows: ⊚ meanssufficient luminance; Δ means further inferior luminance to that of theembossed sheet obtained in Experiments; and X means no luminance. TABLE1 Experiment Comparison 1 2 1 2 3 Reflecting properties ⊚ ⊚ X X Δ

[0135] From Table 1, it is understood that the embossed sheets 11Aobtained in Experiments 1 and 2 are processed through the patterntransfer step, the luster step, and the peeling step according to thepresent invention, thus having sufficient luminance, and naturally, thesatisfying reflecting properties.

[0136] In the emboss patter process relating to these experiments, thetemperature of the area of the emboss patterning roller 13 fortransferring the pattern is 130° C., whereas the temperature of the areaof the roller 13 for peeling the sheet 11 is 60° C. According to theseexperiments, since the emboss pattern processing apparatus having theaforementioned emboss patterning roller 13 is used, it is allowed tocreate the difference in the temperature between the area of the roller13 for transferring the pattern and the area of the roller 13 forpeeling the sheet 11, which is required to obtain the precise patternreproducibility and the peeling properties.

[0137] According to Comparison 1, the pattern transfer itself isprecise. However, the sheet is not smoothly peeled from the rollerbecause of the same high-temperature for peeling as that fortransferring the pattern, thereby the transferred emboss pattern istransfigured.

[0138] According to Comparison 2, the temperature in the patterntransfer step is low, so that the emboss pattern is not preciselytransferred onto the thermoplastic resin sheet 11.

[0139] According to Comparison 3, the luster step is not carried out tothe opposite face of the embossed face of the embossed sheet, resultingin the inferior reflecting properties.

What is claimed is:
 1. A method of an emboss pattern process, comprisingthe steps of: transferring an emboss pattern onto a thermoplastic resinsheet by using an emboss patterning roller; lustering the opposite faceof the embossed face of the thermoplastic resin sheet by using alustering means having a mirror face member; and peeling thethermoplastic resin sheet from the emboss patterning roller at a lowertemperature than a temperature for transferring the emboss pattern. 2.The method of the emboss pattern process according to claim 1 , whereinsaid temperature for transferring the emboss pattern is more than Vicatsoftening point of the thermoplastic resin sheet; and wherein saidtemperature for peeling the thermoplastic resin sheet from the embosspatterning roller is from 10° C. to 150° C. lower temperature than saidtemperature for transferring the emboss pattern.
 3. The method of theemboss pattern process according to claim 1 wherein the opposite face ofthe embossed face of the thermoplastic resin sheet is lustered by thelustering means with a face-pressure of more than 0.01 MPa.
 4. Embosspattern processing apparatus, comprising: an emboss patterning rollerfor transferring the emboss pattern onto a thermoplastic resin sheet; alustering means, having a mirror face member, for lustering the oppositeface of the embossed face of the thermoplastic resin sheet; and acooling means for cooling the thermoplastic resin sheet, peeled fromsaid emboss patterning roller, to a lower temperature than a temperaturefor transferring the emboss pattern.
 5. The emboss pattern processingapparatus according to claim 4 , wherein said emboss patterning rollerhas a roller body having a face for embossing a pattern, and sealingrings attached on each side face of the roller body, the roller body andthe sealing ring having a passage for flowing a temperature controllingmedium for cooling from the sealing ring through the roller body to theother sealing ring.
 6. The emboss pattern processing apparatus accordingto claim 5 , wherein said passage in said roller body is pluralpassage-tubes formed along and in the vicinity of the outercircumferential face of said roller body.
 7. The emboss patternprocessing apparatus according to claim 6 , wherein said sealing ring isformed therein with a groove linking to some of passage-tubes of saidall plural passage-tubes in said roller body.
 8. The emboss patternprocessing apparatus according to claim 7 : wherein said sealing ring isformed therein with a passage for flowing a temperature controllingmedium for heating in addition to said passage for flowing thetemperature controlling medium for cooling; and wherein said sealingring therein has grooves linking to said passages.
 9. The emboss patternprocessing apparatus according to claim 4 , wherein said mirror facemember of the lustering means has the degree of surface roughness ofless than 3S.
 10. The emboss pattern processing apparatus according toclaim 4 , wherein said mirror face member of the lustering means is ametal belt.
 11. The emboss pattern processing apparatus according toclaim 5 , wherein said roller body has an outer cylinder section havingthe face for embossing the pattern, a middle cylinder section havingsaid passage which is inserted into the inside of the outer cylindersection, and an inner cylinder section inserted into the inside of themiddle cylinder section, the middle cylinder section having a greaterlinear expansion coefficient than a linear expansion coefficient of theouter cylinder section, and the inner circumferential face of the middlecylinder section being formed to make a tapered shape having the samedegree angle as a tapered shape created by the outer circumferentialface of the inner cylinder section.
 12. The emboss pattern processingapparatus according to claim 5 , wherein said roller body of said embosspatterning roller is coupled with a rotation shaft for rotating saidroller body, the rotation shaft being passed through said sealing rings.13. The emboss pattern processing apparatus according to claim 4 ,further comprising a heating means for heating an part of said rollerbefore the emboss pattern is transferred and being provided in thevicinity of said emboss patterning roller.
 14. The emboss patternprocessing apparatus according to claim 4 , wherein said emboss patternis a cube corner type.
 15. An embossed pattern sheet produced by thefollowing method: transferring an emboss pattern onto a thermoplasticresin sheet by using an emboss patterning roller; lustering the oppositeface of the embossed face of the thermoplastic resin sheet by using alustering means having a mirror face member; and peeling thethermoplastic resin sheet from the emboss patterning roller at a lowertemperature than a temperature for transferring the emboss pattern. 16.The embossed pattern sheet according to claim 15 , wherein saidtemperature for transferring the emboss pattern is more than Vicatsoftening point of the thermoplastic resin sheet; and wherein saidtemperature for peeling the thermoplastic resin sheet from the embosspatterning roller is from 10° C. to 150° C. lower temperature than saidtemperature for transferring the emboss pattern.
 17. The embossedpattern sheet according to claim 15 , wherein the opposite face of theembossed face of the thermoplastic resin sheet is lustered by thelustering means with a face-pressure of more than 0.01 MPa.